'LABYRINTHITIS
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r. 181. Anatomical relations concerned in dealing with
j labyrinth. 1, Horizontal part of canal for facial nerve;
Lateral semicircular canal; 3, Superior vertical canal;
Posterior vertical canal; 5, Bony wall of sigmoid sinus;
Vertical portion of canal for facial nerve; 7, Oval
ndow; 8, Anterior wall of bony meatus; 9, Promontory.
Fig. 182. Neumann's labyrinth operation.
After the radical mastoid operation has been
completed, a further removal of bone in a
medial direction opens up the posterior
vertical canal.
'Y»V
Fig. 183. Neumann's labyrinth operation. Still
further removal of bone opens up the lateral or
horizontal canal.
Fig. 184. Neumann's operation. The smooth
or medial end of the lateral canal is followed
up into the vestibule, and, later, the pro-
montory is removed by a gouge cut which joins
the oval and round windows. The facial canal
is seen intact between these two openings into
the vestibule.
the acute onset of symptoms follow a known chronic otitis media, or have
been caused by injury during mastoid surgery, exploration of the labyrinth
should be undertaken. There are two standard operations. Hinsberg's con-
sists in performing a radical mastoidectomy, opening into the horizontal
(lateral) semicircular canal, removing the stapes and opening the promon-
tory. Neumann's is more radical in that it opens the two vertical semi-
circular canals as well (Figs. 181-184).